vcl/source/filter/ipdf/pdfread.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include "pdfread.hxx"
  11
  12 #include <config_features.h>
  13
  14 #if HAVE_FEATURE_PDFIUM
  15 #ifdef WNT
  16 #include <prewin.h>
  17 #endif
  18 #include <fpdfview.h>
  19 #include <fpdf_edit.h>
  20 #include <fpdf_save.h>
  21 #ifdef WNT
  22 #include <postwin.h>
  23 #endif
  24 #endif
  25
  26 #include <vcl/bitmapaccess.hxx>
  27
  28 using namespace com::sun::star;
  29
  30 namespace
  31 {
  32
  33 #if HAVE_FEATURE_PDFIUM
  34
  35 /// Callback class to be used with FPDF_SaveWithVersion().
  36 struct CompatibleWriter : public FPDF_FILEWRITE
  37 {
  38 public:
  39     CompatibleWriter();
  40     static int WriteBlockCallback(FPDF_FILEWRITE* pFileWrite, const void* pData, unsigned long nSize);
  41
  42     SvMemoryStream m_aStream;
  43 };
  44
  45 CompatibleWriter::CompatibleWriter()
  46 {
  47     FPDF_FILEWRITE::version = 1;
  48     FPDF_FILEWRITE::WriteBlock = CompatibleWriter::WriteBlockCallback;
  49 }
  50
  51 int CompatibleWriter::WriteBlockCallback(FPDF_FILEWRITE* pFileWrite, const void* pData, unsigned long nSize)
  52 {
  53     auto pImpl = static_cast<CompatibleWriter*>(pFileWrite);
  54     pImpl->m_aStream.WriteBytes(pData, nSize);
  55     return 1;
  56 }
  57
  58 /// Convert to inch, then assume 96 DPI.
  59 double pointToPixel(double fPoint)
  60 {
  61     return fPoint / 72 * 96;
  62 }
  63
  64 /// Does PDF to bitmap conversion using pdfium.
  65 bool generatePreview(SvStream& rStream, Graphic& rGraphic)
  66 {
  67     FPDF_LIBRARY_CONFIG aConfig;
  68     aConfig.version = 2;
  69     aConfig.m_pUserFontPaths = nullptr;
  70     aConfig.m_pIsolate = nullptr;
  71     aConfig.m_v8EmbedderSlot = 0;
  72     FPDF_InitLibraryWithConfig(&aConfig);
  73
  74     // Read input into a buffer.
  75     SvMemoryStream aInBuffer;
  76     aInBuffer.WriteStream(rStream);
  77
  78     // Load the buffer using pdfium.
  79     FPDF_DOCUMENT pPdfDocument = FPDF_LoadMemDocument(aInBuffer.GetData(), aInBuffer.GetSize(), /*password=*/nullptr);
  80     if (!pPdfDocument)
  81         return false;
  82
  83     // Render the first page.
  84     FPDF_PAGE pPdfPage = FPDF_LoadPage(pPdfDocument, /*page_index=*/0);
  85     if (!pPdfPage)
  86         return false;
  87
  88     // Returned unit is points, convert that to pixel.
  89     size_t nPageWidth = pointToPixel(FPDF_GetPageWidth(pPdfPage));
  90     size_t nPageHeight = pointToPixel(FPDF_GetPageHeight(pPdfPage));
  91     FPDF_BITMAP pPdfBitmap = FPDFBitmap_Create(nPageWidth, nPageHeight, /*alpha=*/1);
  92     if (!pPdfBitmap)
  93         return false;
  94
  95     FPDF_DWORD nColor = FPDFPage_HasTransparency(pPdfPage) ? 0x00000000 : 0xFFFFFFFF;
  96     FPDFBitmap_FillRect(pPdfBitmap, 0, 0, nPageWidth, nPageHeight, nColor);
  97     FPDF_RenderPageBitmap(pPdfBitmap, pPdfPage, /*start_x=*/0, /*start_y=*/0, nPageWidth, nPageHeight, /*rotate=*/0, /*flags=*/0);
  98
  99     // Save the buffer as a bitmap.
 100     Bitmap aBitmap(Size(nPageWidth, nPageHeight), 24);
 101     {
 102         Bitmap::ScopedWriteAccess pWriteAccess(aBitmap);
 103         auto pPdfBuffer = static_cast<ConstScanline>(FPDFBitmap_GetBuffer(pPdfBitmap));
 104         for (size_t nRow = 0; nRow < nPageHeight; ++nRow)
 105         {
 106             int nStride = FPDFBitmap_GetStride(pPdfBitmap);
 107             ConstScanline pPdfLine = pPdfBuffer + (nStride * nRow);
 108             // pdfium byte order is BGRA.
 109             pWriteAccess->CopyScanline(nRow, pPdfLine, ScanlineFormat::N32BitTcBgra, nStride);
 110         }
 111     }
 112     rGraphic = aBitmap;
 113
 114     FPDFBitmap_Destroy(pPdfBitmap);
 115     FPDF_ClosePage(pPdfPage);
 116     FPDF_CloseDocument(pPdfDocument);
 117     FPDF_DestroyLibrary();
 118
 119     return true;
 120 }
 121
 122 /// Decide if PDF data is old enough to be compatible.
 123 bool isCompatible(SvStream& rInStream)
 124 {
 125     // %PDF-x.y
 126     sal_uInt8 aFirstBytes[8];
 127     rInStream.Seek(STREAM_SEEK_TO_BEGIN);
 128     sal_uLong nRead = rInStream.ReadBytes(aFirstBytes, 8);
 129     if (nRead < 8)
 130         return false;
 131
 132     if ((aFirstBytes[0] != '%' || aFirstBytes[1] != 'P' || aFirstBytes[2] != 'D' || aFirstBytes[3] != 'F' || aFirstBytes[4] != '-'))
 133         return false;
 134
 135     sal_Int32 nMajor = OString(aFirstBytes[5]).toInt32();
 136     sal_Int32 nMinor = OString(aFirstBytes[7]).toInt32();
 137     if (nMajor > 1 || (nMajor == 1 && nMinor > 4))
 138         return false;
 139
 140     return true;
 141 }
 142
 143 /// Takes care of transparently downgrading the version of the PDF stream in
 144 /// case it's too new for our PDF export.
 145 bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream)
 146 {
 147     bool bCompatible = isCompatible(rInStream);
 148     rInStream.Seek(STREAM_SEEK_TO_BEGIN);
 149     if (bCompatible)
 150         // Not converting.
 151         rOutStream.WriteStream(rInStream);
 152     else
 153     {
 154         // Downconvert to PDF-1.4.
 155         FPDF_LIBRARY_CONFIG aConfig;
 156         aConfig.version = 2;
 157         aConfig.m_pUserFontPaths = nullptr;
 158         aConfig.m_pIsolate = nullptr;
 159         aConfig.m_v8EmbedderSlot = 0;
 160         FPDF_InitLibraryWithConfig(&aConfig);
 161
 162         // Read input into a buffer.
 163         SvMemoryStream aInBuffer;
 164         aInBuffer.WriteStream(rInStream);
 165
 166         // Load the buffer using pdfium.
 167         FPDF_DOCUMENT pPdfDocument = FPDF_LoadMemDocument(aInBuffer.GetData(), aInBuffer.GetSize(), /*password=*/nullptr);
 168         if (!pPdfDocument)
 169             return false;
 170
 171         CompatibleWriter aWriter;
 172         // 14 means PDF-1.4.
 173         if (!FPDF_SaveWithVersion(pPdfDocument, &aWriter, 0, 14))
 174             return false;
 175
 176         FPDF_CloseDocument(pPdfDocument);
 177         FPDF_DestroyLibrary();
 178
 179         aWriter.m_aStream.Seek(STREAM_SEEK_TO_BEGIN);
 180         rOutStream.WriteStream(aWriter.m_aStream);
 181     }
 182
 183     return rOutStream.good();
 184 }
 185 #else
 186 bool generatePreview(SvStream& rStream, Graphic& rGraphic)
 187 {
 188     (void)rStream;
 189     (void)rGraphic;
 190
 191     return true;
 192 }
 193
 194 bool getCompatibleStream(SvStream& rInStream, SvStream& rOutStream)
 195 {
 196     rInStream.Seek(STREAM_SEEK_TO_BEGIN);
 197     rOutStream.WriteStream(rInStream);
 198     return rOutStream.good();
 199 }
 200 #endif // HAVE_FEATURE_PDFIUM
 201
 202 }
 203
 204 namespace vcl
 205 {
 206
 207 bool ImportPDF(SvStream& rStream, Graphic& rGraphic)
 208 {
 209     // Get the preview of the first page.
 210     if (!generatePreview(rStream, rGraphic))
 211         return false;
 212
 213     // Save the original PDF stream for later use.
 214     SvMemoryStream aMemoryStream;
 215     if (!getCompatibleStream(rStream, aMemoryStream))
 216         return false;
 217
 218     aMemoryStream.Seek(STREAM_SEEK_TO_END);
 219     uno::Sequence<sal_Int8> aPdfData(aMemoryStream.Tell());
 220     aMemoryStream.Seek(STREAM_SEEK_TO_BEGIN);
 221     aMemoryStream.ReadBytes(aPdfData.getArray(), aPdfData.getLength());
 222     rGraphic.setPdfData(aPdfData);
 223
 224     return true;
 225 }
 226
 227 }
 228
 229 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */